But they taste so good. Enjoy…
By Lisa Winter
J. Kenji López-Alt, a restaurant-trained chef and managing director of the blog Serious Eats, performed an experiment that explored why fast food burgers seem immortal. He came up with five different hypotheses based on what he knows inhibits mold growth: presence of some special preservative in the meat or bun, high salt content in the burger, low moisture content, no mold spores ever coming into contact with the burger, or no air where the burger was prepared.
Nine different burger combinations were made by mixing and matching the buns and patties from McDonald’s and from his kitchen. Some of his patties had added salt, while others did not, and he also varied the types of packaging. His hands never made direct contact with any of the burgers, which were all left in the open air.
More than three weeks later, the McDonald’s food hadn’t rotted, but neither had the homemade patties. The homemade patty with no added salt looked no different than the those with extra salt, indicating it wasn’t the causal factor.
The key appeared to be moisture levels. The burgers had each lost a quarter of their weight within the first week, indicating that they had dried out. Without moisture, the mold can’t grow. Since McDonald’s uses thin patties with a lot of surface area, they quickly dry out before they can start to rot. This is the entire principle behind beef jerky. A McDonald’s burger sealed in a plastic bag will be completely consumed with mold within a week.
Read more: IFL Science